Spontaneous rupture of the spleen: ultrasound patterns, diagnosis and follow-up.

Spontaneous rupture of the spleen is an extremely rare complication usually of infectious diseases or disorders of the haematopoietic system and has been described mostly in case reports. The incidence, symptoms, causes, therapy, and prognosis are poorly defined. From July 1985 to January 2000 41 patients with spontaneous splenic rupture were diagnosed by abdominal ultrasound and confirmed by splenectomy (n=12), CT (n=15), and ultrasound follow up (n=26). An ultrasound grading system was retrospectively established based on the degree of splenic injury (grade 0-2=low grade injury, grade 3=high grade injury) and correlated with surgical procedures. 30 day mortality rate was studied in relation to underlying disorders, ultrasound grades and treatment decisions. 21 patients had underlying malignant disorders (group I) and 20 patients had benign diseases (group II). Between group I and II we observed a highly significant difference in 30 day mortality rates (n=7; 38.1% vs n=1; 5%, p<0.01), but no significant difference in high grade injury rate (n=3; 14.3% vs n=2; 10.0%; p=ns) and surgical treatment rate (n=5; 23.8% vs n=7; 35.0%; p=ns). Depending on ultrasound grades the surgical procedures were 0% for grade 0, 16.7% for grade 1, 30.4% for grade 2, and 60% for grade 3. There were no significant differences between patients, who died within the first 30 days (n=9) and those who survived more than 30 days (n=32) regarding high grade splenic injury rate (n=0; 0% vs n=5; 15.6%; p=ns), and surgical treatment rate (n=2; 22.2% vs n=10; 31.2%; p=ns). Spontaneous rupture of the spleen is an extremely rare event. It is associated with a high mortality rate within 30 days in patients with malignant disease. Sonomorphologic grading is helpful for treatment decisions. 30 day mortality rate is correlated with neither ultrasound grades, nor surgical treatment rates.